Unbound does not start - no outgoing traffic

[danbet]

If I connect the OPNsense box in a LAN, all services are startet. But as soon I connect it at the WAN, Unbound DNS does not start. Dnsmasq-DNS starts, but outgoing traffic does not work. DNS queries works, but I cannot show websites, even with the IP-Address. Incoming traffic works. I have a public IP-Address from the provider.

What's the problem with unbound or the WAN connection?